DK Ancient China (This is the one I'll buy)
Chinese Children's Favorite Stories (good illustrations; a light read)
Ms. Frizzle's Adventures: Imperial China (my kids are in love with Ms. Frizzle and that Magic School Bus)
If I Were a Kid in Ancient China (I actually haven't sampled this series yet)
Moonbeams, Dumplings, and Dragon Boats: a Treasury of Chinese Holiday Tales, Activities and Recipes (I'm not sure if this is more modern or ancient China)
Tales of a Chinese Grandmother looks good, but has far more words than pictures. We might turn to it our next time through ancient history, in fifth grade.
Aside from the DK Ancient China book, what we actually read will depend on what our local library has, but I save so much money taking my Amazon list to the local library.